This invention was made in the course of, or under, a contract with the Energy Research and Development Administration.
In the fabrication of nuclear fuel microspheres it is necessary to perform certain analyses on random samples withdrawn from a bulk supply. One such analysis or test is the measurement of individual particle diameter to ascertain size distribution. Preferably these tests are performed beginning with the bare fuel kernel and then after the deposition of any coatings such as the pyrolytic carbon coating applied to most particles. The initial kernel may be, for example, about 380 .mu.m in diameter where the fully-coated particle may be about 800 .mu.m. Other analyses, such as density, uniformity of size, etc., are typically performed at various stages of fabrication.
One problem that exists in connection with any of these analyses relates to the sampling technique whereby a representative sample of proper size is obtained. Furthermore, the desired size of the sample may vary for different analyses, or because of a different type particle. In addition, all sampling must be conducted remotely particularly when recycle material is being utilized due to higher radiation levels. Thus there exists a need for a remotely-operated variable-percentage sampler wherein the sampler will provide the desired size sample of particles for subsequent analyses. This need has been met in the present invention in a manner to be described hereinbelow.